One embodiment of a nonvolatile memory device includes a memory cell array including a plurality of multi-level cells, and a control unit configured to determine a characteristic of data to be stored in the memory cell array. The control unit is configured to select one of plural multi-bit programming methods based on the determination. Data is stored in the memory cell array according to the selected multi-bit programming method, and at least one of the plural multi-bit programming methods maintains least significant bit data when there is a program fail of most significant bit data.